1 | // tPolyModel.cpp  |
2 | //  |
3 | // This file implements tScene polygonal models. A tPolyModel contains a tMesh and a functional interface over it.  |
4 | //  |
5 | // Copyright (c) 2006, 2017, 2020 Tristan Grimmer.  |
6 | // Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby  |
7 | // granted, provided that the above copyright notice and this permission notice appear in all copies.  |
8 | //  |
9 | // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL  |
10 | // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,  |
11 | // INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN  |
12 | // AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR  |
13 | // PERFORMANCE OF THIS SOFTWARE.  |
14 |   |
15 | #include <Foundation/tFundamentals.h>  |
16 | #include "Scene/tPolyModel.h"  |
17 | using namespace tMath;  |
18 | namespace tScene  |
19 | {  |
20 |   |
21 |   |
22 | void tPolyModel::Save(tChunkWriter& chunk) const  |
23 | {  |
24 | chunk.Begin(tChunkID::Scene_PolyModel);  |
25 | {  |
26 | tObject::Save(chunk);  |
27 |   |
28 | chunk.Begin(tChunkID::Core_Bool);  |
29 | {  |
30 | chunk.Write(IsLodGroupMember);  |
31 | }  |
32 | chunk.End();  |
33 |   |
34 | Mesh.Save(chunk);  |
35 | }  |
36 | chunk.End();  |
37 | }  |
38 |   |
39 |   |
40 | void tPolyModel::Load(const tChunk& modelChunk)  |
41 | {  |
42 | tAssert(modelChunk.ID() == tChunkID::Scene_PolyModel);  |
43 | Clear();  |
44 |   |
45 | for (tChunk chunk = modelChunk.First(); chunk.Valid(); chunk = chunk.Next())  |
46 | {  |
47 | switch (chunk.ID())  |
48 | {  |
49 | case tChunkID::Scene_Object:  |
50 | tObject::Load(chunk);  |
51 | break;  |
52 |   |
53 | case tChunkID::Core_Bool:  |
54 | chunk.GetItem(IsLodGroupMember);  |
55 | break;  |
56 |   |
57 | case tChunkID::Scene_Mesh:  |
58 | Mesh.Load(chunk);  |
59 | break;  |
60 | }  |
61 | }  |
62 | }  |
63 |   |
64 |   |
65 | float tPolyModel::ComputeBoundingRadius() const  |
66 | {  |
67 | float maxRadiusSq = 0.0f;  |
68 | for (int v = 0; v < Mesh.NumVertPositions; v++)  |
69 | {  |
70 | float distSq = Mesh.VertTablePositions[v].LengthSq();  |
71 | if (distSq > maxRadiusSq)  |
72 | maxRadiusSq = distSq;  |
73 | }  |
74 |   |
75 | return tSqrt(maxRadiusSq);  |
76 | }  |
77 |   |
78 |   |
79 | void tPolyModel::ComputeMinMaxRadius(float& minRadius, float& maxRadius) const  |
80 | {  |
81 | float minRadiusSq = Infinity;  |
82 | float maxRadiusSq = 0.0f;  |
83 | for (int v = 0; v < Mesh.NumVertPositions; v++)  |
84 | {  |
85 | float distSq = Mesh.VertTablePositions[v].LengthSq();  |
86 | if (distSq > maxRadiusSq)  |
87 | maxRadiusSq = distSq;  |
88 |   |
89 | if (distSq < minRadiusSq)  |
90 | minRadiusSq = distSq;  |
91 | }  |
92 |   |
93 | minRadius = tSqrt(minRadiusSq);  |
94 | maxRadius = tSqrt(maxRadiusSq);  |
95 | }  |
96 |   |
97 |   |
98 | tBox tPolyModel::ComputeBoundingBox() const  |
99 | {  |
100 | tBox boundingBox;  |
101 |   |
102 | for (int v = 0; v < Mesh.NumVertPositions; v++)  |
103 | boundingBox.AddPoint(Mesh.VertTablePositions[v]);  |
104 |   |
105 | return boundingBox;  |
106 | }  |
107 |   |
108 |   |
109 | float tPolyModel::ComputeApproxArea() const  |
110 | {  |
111 | // See http://mathworld.wolfram.com/TriangleArea.html and http://mathworld.wolfram.com/Circumradius.html  |
112 | float area = 0.0f;  |
113 | for (int f = 0; f < Mesh.NumFaces; f++)  |
114 | {  |
115 | int start = f*3;  |
116 | tMath::tTriFace& face = Mesh.FaceTableVertPositionIndices[f];  |
117 |   |
118 | tVector3& v0 = Mesh.VertTablePositions[face.Index[0]];  |
119 | tVector3& v1 = Mesh.VertTablePositions[face.Index[1]];  |
120 | tVector3& v2 = Mesh.VertTablePositions[face.Index[2]];  |
121 | tVector3 A = v1 - v0; float a = A.NormalizeGetLength();  |
122 | tVector3 B = v2 - v0; float b = B.NormalizeGetLength();  |
123 | tVector3 C = v1 - v2; float c = C.NormalizeGetLength();  |
124 |   |
125 | // The link above explains this name.  |
126 | float circumradius = a*b*c / tMath::tSqrt((a+b+c)*(b+c+-a)*(c+a-b)*(a+b-c));  |
127 | float triArea = a*b*c / (4.0f * circumradius);  |
128 | area += triArea;  |
129 | }  |
130 |   |
131 | return area;  |
132 | }  |
133 |   |
134 |   |
135 | }  |
136 | |